Infections of skin, nails, hair, or mucous membranes by fungi are common.
Onychomycosis, in particular, is a frequent fungal infection of nails, involving up to about 15% of adult individuals between the ages of about 40 to about 60 years. Delivery of antifungal agents through the nail and into the nail beds as well as the surrounding skin has been difficult to date, and minimally effective.